Recent years have seen the growing popularity of illuminating apparatuses using light-emitting modules including light-emitting elements such as light-emitting diodes (LED) as substitutes for incandescent lamps.
Patent Literature (PTL) 1 (Japanese Unexamined Patent Application Publication No. 2007-536708) discloses an illuminating apparatus to which plural flat panel light sources are electrically connected.
FIG. 17 is an outline configuration diagram of a conventional light-emitting unit apparatus disclosed in PTL 1. The figure illustrates a light-emitting unit apparatus which includes: plural light-emitting units 905; and communication lines connected to the light-emitting units 905, for communicating control signals. The respective light-emitting units 905 have plural electrical contacts for the supply of power and, by being electrically connected to each other, are able to supply power to adjacent light-emitting units 905. Furthermore, PTL 1 discloses that each light-emitting unit 905 includes a control device and, through signal communication between adjacent control devices, plural light-emitting units 905 can operate in conjunction with one other. Furthermore, each light-emitting unit 905 is controlled so that a constant current flows to the light-emitting element in order to produce a constant luminance.